Refrigerating apparatus



Oct. 28, 1930. R. H. CHILTON 1,779,409

' REFRIGERATING APPARATUS Filed Sept. 28, 1927 Patented Oct. 28, 1930 UNITED STATES PATENT "OFFICE.

RAIRH H. CHILTON, OI! DAYTON, OHIO, ASSIGNOR, BY ASSIGNMENTS, '10 FRIGIDAIRE CORPORATION, A. CORPORATION 01 DELAWARE BEFRIGERA'IING APPARATUS Application. filed September as, 1927. Serial No. 222,649.

The present invention relates to refrigerating systems and the control thereof.

One of the objects of the present invention is to provide an improved refrigerating sys- 5 tern of the type including a plurality of cooling units or cooling circuits which are cooled by the circulation of refrigerating medium therein b a mechanism common to both units,

and in w ich the temperature of one of said units or circuits, is lowered quickly relative to the other.

Another object of the present invention is to provide for the control of a refrigerating system of the above mentioned type whereby the heat exchange between one of the units and the substance cooled thereby is greater than the heat exchange between another of said units andthe substance cooled by the latter.

In carrying out the above objects it is a further object to control the flow of refrigerant medium whereby the demand for cooling by one of said units is satisfied prior to the demand by another unit.

A still further object of the present invention. is to improve the efliciency of a refrigerating system of the type which is utilized for cooling substances to different temperatures as for example, the cooling of water to freezing temperature and for cooling air to a higher temperature; In that type of system, the refrigerant circulating means must operate at a relatively low back pressure in order to cool, for example,- the water to freezing temperature. In the present invention the efiiciency of the system is increased by operating the system at the necessary relatively low -back pressure onlv durlng the perlod necessary for cooling the substance to its desired relatively low temperature and thereafter operating at a higher back pressure for coollng the other substances.

Another object of the present invention 1s to provide improved means for'precoolingrefrigerating medium supplied to a cooling unit.

Further objects and advantages of the present invention will be apparent from the following description, reference belng had to the accompanying drawings, wherem a preferred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic view of the improved refrigerating system; and

F gs. 2 and 3 each are longitudinal sectional vlews of certain valves used in the system.

Referrlng to the drawings, there is shown a cooling unit 20 and a cooling unit 21. Refrrgeratmg medium is supplied to the cooling un1t 20 through a pipe 22 and the fiow of the medium to the unit is controlled by a float valve 23. Refrigerating medium is supplied to the cooling unit 21 through a pipe 25 whlch flow is controlled by a pressure-reducing valve 26. A valve 28 is connected with an outletpipe 29 of the cooling unit 20 and an outlgt pipe 30 of the cooling unit 21. This valve 8 is arran ed to selectively control the flow of the re rigerating medium either from one or the other of said cooling units. Refrigerating medium is withdrawn from the cooling units 20 and 21 through the valve 28 by a pipe 32.

Any suitable means may be provided for circulating the refrigerating medium through the cooling units 20 and 21 but for the purpose of illustrating the present invention, I have shown a compressor 35 having its low pressure portion connected with the pipe 32 and having its high pressure portion connected by pipe 36 with a condenser 37 The outlet of the condenser is connected with the pipe 22 for supplying refrigerating medium to the cooling units. The compressor is driven by a motor 38 which is started and stopped by a controller 40 and this controller is responsive to a thermo bulb 41 and a thermo bulb 42 which thermo bulbs are under the influence of the temperatures of cooling units 20 and 21 respectively. The'thermo bulb 42 is also utilized for controlling the valve as will appear in detail hereinafter. Referring .more in detail to the drawings and particularly to Fig. 2, the valve 28 which selectively controls the flow of refrigerating medium either from cooling unit 20 or 21 includes a body 45. The body 45 is provided with a chamber 46, which receives refrigerant from the pipe 29, and an outlet 47 of the P chamber 46 is controlled by a valve 48. The valve body is provided with a second chamber 49 separated from the chamber 46 by a wall 50, which wall provides a guide for the stem of the valve 48. A spring 51 is interposed between the wall and a spring clip 52 carried by the end of the stem of the valve 48, and normally tends to hold the valve 48 to close the port 47. A valve plate 54 is suitably secured on the top of the valve body 45 and is provided with a chamber 55 which is in communication with pipe 30 and pipe 32. The inlet to the chamber 55 from the pipe 30 is provided with a valve seat 56 which is in alignment with the port 47 and is arranged to be opened and closed by the valve 48. A valve plate 58 is carried on the bottom of valve body 45 by screws 59 and a corrugated diaphragm 60 is interposed between the body 45 and the plate 58 which diaphragm provides a lower flexible wall for the chamber 49 and cooperates with the plate 58 to provide a chamber 62. Chamber 62 communicates with a pipe 63 in which pipe there is adapted to be a change in pressure which change in pressure will cause the diaphragm 60 to move upwardly. A spring 64 interposed between the wall 50 in a plate 65, on diaphragm 6O normally tends to hold the diaphragm in the position shown in the drawing. However, when there is an increase in pressure in the pipe 63 and likewise in chamber 62, the diaphragm 60 will move upwardly and after it has moved beyond its dead center position, it will engage the stem of the valve 48 to thereby open the port 47 and close communication between the pipe 30 and the chamber 55.

Thus it is apparent that when the valve is in the position shown in the drawings refrigerating medium will not be withdrawn from the cooling unit 20 through the pipe 29 because the port 47 is closed by valve 48. In this position of the valve, refrigerating medium can be withdrawn from the cooling unit 21 through the pipe 30, chamber 55 and pipe 32. When however the valve 48 is closed upon its seat 56 refrigerant can not pass from pipes 30 and 32 and therefore refrigerant Wlll be withdrawn from cooling unit 21 and when valve 48 isclosed upon seat 56 intercommunication is established between pipe 29 and pipe 32 through the port 47 whereby refrigerating medium can be withdrawn from cooling unit 20.

The thermo bulb 42 is herein shown as a freezing thermostat, namely, one in which a quantity of water and oil is contained therein. Freezing of the water will cause an 1ncreased pressure within the thermo bulb 42 which pressure is transmitted by a pipe 68 and pipe 63 to the chamber 62 of the valve 28. Thus when water is frozen within the bulb 42 the valve 28 actuates to discontinue the withdrawal of refrigerating medium from the cooling unit 21'and connects the compressor 35 so as to withdraw refrigerating medium from the cooling unit 20.

One form of expansion valve 26 which controls the flow of the refrigerating medium to the cooling unit 21 in response to the pressure within said cooling unit, is shown in detail in Fig. 3. This valve comprises a body 69 having an inlet opening 70 connected with pipe 25 and an outlet opening 71 connected directly with the cooling unit 21. The inlet opening 70iscontrolled by a needle valve 72 which is carried by a yoke 73 and this yoke is suitably secured to a diaphragm 74. Diaphragm 74 is held in position by a plate 75. A spring 76 normally tends to hold the valve. 72 in closed position. However, decrease in pressure within the cooling unit 21 and likewise in valve body chamber 77 causes the diaphragm 74 to move inwardly to open the valve 72 to permit more refrigerant to enter the cooling unit 21. It is to be understood that the type of valve herein shown is merely for the purpose of illustrating the present invention and that any suitable pressure-reducing means may be utilized in place of that shown.

A preferred manner of supplying refrigerating medium through the valve 26 to the cooling unit 21 is to connect the pipe 25 below the liquid level within the cooling unit 20 whereby the refrigerant delivered to the cooling unit 21 is precooled. In this manner the temperature within the cooling unit 21 can be lowered quickly. Another method of supplying refrigerant to the cooling unit 21 through the valve 26 would be to by-pass unit 20 as by connecting pipe 25 with pipe 22 by a pipe 80.

The controller 40 for the motor 38 includes contacts 82 and 83 which are operated by a snap switch 84. This snap switch is connected by a link 85 to a lever 86 pivoted at 87. A

metal bellows 89 is arranged to actuate lever 86 in one direction and is connected by a pipe 90 with the thermo bulb 41 and a spring 91 counteracts the movement of the bellows 89. The bulb 41, pi e 90 and bellows 89 contain a volatile fluid w ich is responsive to the temperature of the coolin unit 20. When the temperature of the coo ing unit 20 attains a predetermined low value the fluid, within the thermostatic circuit, will contract and the spring 91 will actuate the lever 86 to operate the snap switch 84 whereby to separate contact 83 from 82 provided however, that there is no demand for refrigeration by the cooling unit 21. An increase of temperature of cooling unit 20 causes the fluid in the thermostat 41 to expand and this expansion will cause the bellows 89 to actuate the contacts 82 and 83 to start the motor.

A metal bellows 93 is connected by a pipe 94 with the ipe 68 to thermo bulb 42. A stem 95, whic is attached to the movable end of the bellows 93, extends through the lever 86 and is provided with a head 96 which head is arranged to engage the underside of lever 86 when the bellows contracts to close contacts 83 and 82. Movement of the bellows in the opposite direction will not actuate the lever 86. When the ice within the thermo bulb melts, the pressure therein and likewise within the pipe 68 and 94 and bellows 93 decrease, causmg the collapsing of said bellows whereby contact 83 will engage contact 82 to close the motor circuit. It is apparent from the foregoing that the motor is started and stopped in'response to aliigh and low temperature respectively of the cooling unit 20 and is started in response to a high temperature of a cooling unit 21.

The present invention is particularly useful where it is desirable that one of the refrigerating demands be prior to the other, as for example, where it is desirable to freeze water or congeal a substance quickly. As here in shown, the demand of the cooling unit 21 is satisfied prior to the demands of the cooling unit 20. If refrigeration is desired in cooling unit 21 thermo bulb 42 will operate tostart the refrigerating cycle and will actuate the valve 28 to prevent the withdrawal of the refrigerant from the. cooling unit 20. Moreover, even though the temperature of the cooling unit 20 has caused the starting of the refrigerating cycle the flow of refrigerant therefrom through the pipe 29 will be discontinued in case there is a demand by the cooling unit 21. In this manner the cooling of unit 21 is accomplished quickly.

By virtue of this invention the efliciencyof the refrigerating system is materially increased. This efficiency is most pronounced when the cooling unit 20 is utilized for cooling a relatively large compartment to a temperature somewhat higher than that required to be obtained by cooling unit 21. For example, if the cooling unit 20 is used for cooling food the desired temperature thereof would be approximately between 30 and 35 F. while if cooling unit 21 is utilized forfreezing or congealing a substance, a much colder temperature would be necessary, as for example, approximately 14 F. Thus, when the compressor withdraws refrigerant from the cooling unit 20, the back pressure is hlgher than when the refrigerant is withdrawn from cooling unit 21 and the compressor and motor will operate more efiiciently. Since the compressor operates at the relatively low back pressure requiredby the cooling unit 21 only a small percentage of time, namely, that necessary for freezing or congealing a substance, or, for maintaining a substance at a predetermined temperature, and at the higher back pressure when withdrawing refrigerant from the cooling unit 20 the larger portion of tune, the efliciency of the system will be greatly increased. Also it will not be necessary to operate the cooling unit 20 at such low tempera ture as to cause condensation of frosting thereon and hence there will be more efiicient transfer of heat between said cooling unit and the air cooled thereby.

In the illustration I have shown the cooling unit 21 as comprising a coil which surrounds ice trays 98 and which coil is inserted in compartment 99 and likewise I have shown cooling unit 20 as being disposed within a separate compartment 100. It is to be understood however, that these cooling units may be contained within the same compartment or cabinet.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A refrigerating system, comprising in combination, a plurality of. cooling units, means for circulating a refrigerant medium through said units, and fluid pressure operated means responsive to the conditions of one of said units for selectively connecting either of said units with the circulating means. v

2. refrigerating system, comprising in combination a plurality of cooling units, means for circulating a refrigerant medium through said units, conduit means connecting said units with the circulating means, said conduit means including a plurality of conduits each connected with one of said cooling units and arranged in parallel circuit relation, a fluid pressure operated valve for obstructing the flow of refrigerant medium through the conduit connecting one of said units, and means responsive to the condition of the other unit for actuating said valve.

3. A refrigerating system, comprising in combination two cooling units, means for said units, and fluid pressure operated means responsive to the conditions of one of said units for obstructing the flow of refrigerant medium through the other cooling unit only.

4. A refrigerating system, comprising in combination, a plurality of cooling units, means for circulating a refrigerant medium through said units, outlet conduits adapted to connect said units with the circulating means, a valve controlling the flow of refrigerant medium through said outlet conduits for selectively connecting either of said units with the circulating means, and means responsive to the conditionsof one of said units for actuating said valve.

5. A refrigerating system, comprising in combination, a cooling unit, means for circulating a refrigerant medium through said unit, conduit means for connecting the outlet of said unit and the circulating means, a,

valve said outlet conduit means, and a single means responsive to the condition of said unit for controlling said valve and for controlling the circulating means.

6. A refrigerating system, comprising m combination, a cooling unit, means for c1 rculating a refrigerant medium through said unit, conduit means connecting the outlet of said unit and the circulating means, a valve in said outlet conduit means, and a single means responsive to the condition of said unit for opening said valve and for rendering said circulating means OPGIBIJVG:

7. A refrigerating system, 00I11PI1S1Ilg lI1 combination, a plurality of cooling units, means for circulating a refrigerant medium through said units, means responsive to the conditions of either of said units for controlling said circulating means, said means including a'device at the outlet of one of sald units for obstructing the flow of refrigerant medium from said units when there is a demand for circulation in the other unit.

8. A refrigerating system, comprising in combination,;, -a plurality of cooling units, means for circulating a refrigerant medium through said units,fmeans res onsive to the demand of one-of said units or circulat 1on of medium fog rendering the circulatmg means operativfand means at the outlet of said unit for obstructing the flow therefrom when there is a demand for circulation in the other unit.

9. A refrigerating system, comprlsing in combination, a cooling unit, a second coohng unit connected with the first cooling unit for receiving refrigerant therefrom. a pressure reducing valve in the connection and res onsive to the condition of the second coo ing unit, and means for withdrawing refrigerant from the units and for condensing said refrigerant and for-forcing same into the first cooling unit.

10. A refrigerating system, comprising in combination, a cooling unit, a valve for maintaining a quantity of liquid refrigerant within the unit, a second cooling umt connected below the liquid level in the first cooling unit for receiving the refrigerant therefrom, a pressure reducing valve between said units and-'responsive-to the condition of the sec ond coolin -unit. and means for withdrawing refrigerant from the units and for condensing said refrigerant and for forcing same into the first cooling unit.

11'. A refrigerating system, comprising in combination, a plurality of cooling units, means for circulating a refrigerating medium through said units, conduit means connecting said units with the circulating means, said conduit means including conduits arranged in parallel circuit relation, one of said conduits connecting the outlet of one of the units with the circulating means and the other of said conduits connecting the other of said units with the circulating means, a valve for obstructing the flow of refrigerating medium through the conduit connecting one of said units, and means responsive to thecondition of the other unit for actuating said valve.

12. A refrigerating system, comprising in I combination, two cooling umts, means for circulating refrigerating medium through said units, conduit means connecting theoutlets of said units with the circulating means, a valve in the conduit means for obstructing the flow of refrigerating medium from one of said units, and means responsive to the condition of the other unit for actuating said valve.

13. A refrigerating system, comprising in combination, a cooling unit, a float actuated valve responsive to the quantity of liquid refrigerant within the cooling unit for controlling the fiow of refrigerant to the unit, a second cooling unit connected with the first cooling unit for receiving refrigerant therefrom, a pressure reducing valve between said units and responsive to the condition of the second cooling unit, and means connected with the cooling units for circulating refrigerant therethrough.

14. A refrigerating system, comprising in combination a cooling unit, a float actuated valve responsive to the quantity of liquid refrigerant within the cooling unit for controlling the fiow of refrigerant to the unit, a second cooling unit connected with the first coolin unit below the liquid level in said first umt for receiving refrigerant therefrom, a pressure reducing valve between said umts and responsive to the condition of the second cooling unit, and means connected with the coolingunits for circulating refrigerant therethrough.

15. A refrigerating system, comprising in combination, a cooling unit, a valve for maintalnmg a quantity of liquid refrigerant in said unit, a second cooling unit connected with the first cooling unit for receiving refrigerant therefrom, a pressure reducing valve between said units and responsive to the condition of the second cooling unit, and means connected with the cooling units for circulating refrigerant therethrough.

16. A refrigerating system, comprising in comblnation, a cooling unit, a second cooling umt connected with the first cooling unit for receiving refrigerant therefrom, means connected with the units for circulatin refr1gerant therethrough, a valve associated with the outlet of the first unit for obstructing the flow of refrigerant therefrom, and means responsive to the condition of the secondunit for actuating said valve.

17. A refrigerating system, comprising in combination a plurality of cooling units, means for circulating a refrigerant medium through said units, a valve at the outlet of III" Ill)

one of said cooling units, and means responsive to a certain condition of another of said units for actuating. said valve for impeding the flow of refrigerant medium through the first unit while permitting unobstructed flow through the second unit and responsive to a difierent condition of the second unit for actuating said valve for permitting the flow through said first unit. i

In testimony whereof I hereto aflix my signature.

' RALPH H. CHILTON. 

